This invention relates to floating islands that are designed to provide highly buoyant, semi-rigid platforms for various applications such as walkways, roadways, docks, piers, water treatment facilities, and bird nesting habitat.
Some embodiments of the present invention may be used as alternatives to footbridges and vehicular bridges. They provide access across ponds, streams and bays, and also provide access to objects such as docks and islands that are situated in water bodies. Floating walkways and roadways may be preferable to conventional pile-supported bridges because they can be less expensive to construct, faster to install, easier to move, and more adaptable to water level fluctuations. Floating walkways and roadways may also be preferable to conventional bridges at locations where the water depth or bottom materials make pile-supported bridges difficult or expensive to install. Floating walkways and roadways may also be preferable at environmentally sensitive locations where the installation of conventional bridges would cause adverse impacts to wildlife or vegetation.
Some embodiments of the present invention may be used to treat contaminated water via mechanical and biological filtration, by circulating contaminated water through the island body for treatment. The relatively high level of buoyancy and semi-rigidity provided by the present invention makes the islands particularly suitable for supporting water pumps, air compressors, and other relatively heavy equipment. This equipment enables the islands to operate efficiently as water-quality remediation devices.
Some embodiments of the present invention may be used to replicate natural nesting habitat for certain birds (e.g., piping plovers) whose populations have diminished due to human-caused reduction in appropriate nesting areas. These birds prefer to nest in gravel flats located in proximity to water. The present invention provides the necessary buoyancy and rigidity to support nesting gravel beds, and thereby provides secure nesting habitat for these birds and other wildlife species.
The islands of the present invention may be manufactured in relatively small and easily transportable units, and then readily joined together at the deployment site to form large, highly buoyant semi-rigid structures. Alternately, an island may be manufactured as a single unit.
Background art floating platforms used as walkways, water treatment devices or nesting habitat obtain their buoyancy from pontoons or floats that are comprised of air-filled chambers or closed-cell foam blocks such as polystyrene foam. The foam blocks may be coated with a protective covering to reduce damage from impact and ultraviolet (UV) light.
Background art floating platforms have several limitations and deficiencies that are overcome by preferred embodiments of the present invention. Background art floating platforms are typically rectangular in shape and recognizable as man-made structures, and they are manufactured from materials that do not support the growth of plants on the top, edges, or interior of the structures. As a result of the materials and methods that are employed to construct background art floating platforms, these structures have low aesthetic value at locations where natural appearance is important. Background art floating platforms also tend to gradually lose buoyancy over time due to factors such as water absorption into the foam flotation, loss of flotation due to impact, ice damage, or waterlogging of the top surface.
Some water bodies experience contamination in the form of excess nutrient inflows from sources such as crop fertilizer, wastewater facility effluent and livestock waste runoff. These excess nutrients, which may include ammonia, nitrate, and phosphate, can promote algae growth and be toxic to fish, wildlife, and humans. Background art floating treatment platforms do not have the combination of high buoyancy, rigidity, natural appearance, and high treatment efficiency.
The background art is characterized by U.S. Pat. Nos. 5,224,292; 5,528,856; 5,766,474; 5,980,738; 6,086,755; and 6,555,219 and U.S. Patent Application Nos. 2003/0051398; 2003/0208954; 2005/0183331; the disclosures of which patents and patent applications are incorporated by reference as if fully set forth herein.